Monday, September 24, 2007

Left decreases, the evil twin--part 2 of right and left leaning decreases

includes 8 illustrations
This is the second in a 4-part series about right and left leaning decreases. The most common RIGHT LEANING DECREASE (knit 2 together) was covered in the first post. Today's post is about the two most common LEFT LEANING DECREASES: slip 1, knit 1, pass the slipped stitch over (psso) and slip, slip, knit (ssk).

Today's post is in two parts.
  • The first part is a simple tutorial about how to make psso and ssk.
  • The second part explains just what it IS about psso and ssk that makes them so sloppy looking (and so different looking from right leaning decreases).
After today's post, the background stuff will be out of the way, and TECHknitting will turn to 2 new ways to make left leaning decreases.


To make PSSO, there are three steps:

1. (below). Slip the first stitch (red) at the tip of your left needle onto your right needle KNITWISE (left arm forward)

2. (below) Knit the next stitch (green). The result will be two stitches on your right needle--the one you slipped (red) and the one you just knit (blue). Insert the tip of your LEFT needle under the left arm of the red stitch (in other words, so the stitch is not twisted) and lift the red stitch over the blue stitch and drop the red stitch from your needle. (The blue stitch stays on your right needle)

3. (below) This is the final result, after the red stitch has been lifted over the blue stitch: only the blue stitch remains on the needle--one stitch where there were two before. The red stitch has been pulled to lie on top of the green stitch, and the slant of the red stitch (leftwards) dominates the decrease.

To make SSK, there are three steps:

1. (below) Ssk starts the same way as psso: you slip the first stitch (red) at the tip of your left needle onto your right needle KNITWISE (left arm forward)

2. (below). For the second step of ssk, you slip the next stitch (green) from left to right needle the same way--KNITWISE, left arm forward. Then, you flick the standing yarn over your right needle, and knit the two stitches together from this position.

3. (below) Here is the final result: The blue stitch is pulled (knitted) through the red and green stitches. Just like psso, only the blue stitch remains on the needle, leaving one stitch where there were two before. The red stitch has been pulled to lie on top of the green stitch, and the slant of the red stitch (leftwards) dominates the decrease.


OK, so now we're ready to talk about the two main reasons why left leaning decreases are all bumpy and slouchy. First, If you look at the diagrams for both psso AND ssk, you'll see that you are manipulating the FIRST STITCH on the needle--the red one. You're manhandling it pretty severely, actually. In both psso and ssk, you grab that red stitch and stretch it out as you slip it from left needle to right needle. This draws extra yarn into that first stitch as the surrounding stitches play "pass-along." In other words, by sliding the first stitch from one needle to another, yarn that would ordinarily lie in surrounding stitches gets pulled up into the loop of the red stitch.

Second, you're changing the orientation of the red stitch--when it was first knitted (assuming you're not a combination knitter) it lay RIGHT arm forward. Slipping that first red stitch KNITWISE makes it lay LEFT arm forward. At the point where the orientation changes from right-arm-forward stitches to left-arm-forward stitches, for various esoteric reasons, slack develops in the yarn. (If you have an interest in yarn orientation, a lot more detail will eventually be posted when TECHknitting addresses "combination knitting.") For right now, suffice it to say that the change in orientation draws even more yarn into the first (red) stitch, in both psso and ssk.

Compare this sequence with k2tog. In k2tog, the top stitch is the SECOND stitch (green stitch), and it is never manhandled at all--it is never pulled up loose, never passed from needle to needle, and its orientation is never changed. (Click here for diagram, click here from more info on k2tog.) The stitch behind the top stitch (the red stitch in the k2tog diagram) never has a chance to pass any slack yarn along to the green stitch--that red stitch is nailed down behind the green stitch in a 1 step motion--it (and all its excess yarn) gets squeezed behind the green stitch before it ever gets a chance to play pass-along with the green stitch, and the one-step motion of k2tog reduces the opportunity for other stitches to pass along too much yarn, either.

The upshot is that, in left leaning decreases, the multi-step procedure means that the first (red) stitch is drawn up all big and sloppy. Then, even more yarn is delivered to the red stitch by the change in orientation. As you can see from the diagrams, psso is the worse offender--you manhandle that red stitch not just once (passing it from left needle to right) but twice (as you grab it and draw it up big in passing it over the blue stitch).

In both psso and ssk, this bumpy, loose, sloppy red stitch is then left to languish on the surface of the fabric. As the photos below demonstrate, left leaning decreases really are the "evil twin," in looks, at least, when compared to right leaning decreases. As you would expect, the extra manhandling of the top stitch means that psso ends up somewhat looser and sloppier than ssk. Yet, although ssk is somewhat better, it also does not approaches k2tog for tidiness. Here is the photographic evidence:

The upper part of each photo is the right leaning decrease--knit two together (k2tog)--which is included for comparison purposes--nice and even, aren't they? The lower part of the first photo (above) is slip 1, knit 1, pass the slipped stitch over (psso), the lower part of the second picture (below) is slip, slip, knit (ssk). Nice and sloppy, huh?
(Don't be confused that these samples are laid on their sides, that's just for illustration. Each swatch was knit so the cast-on edge is to the right, the cast off edge to the left.)

In sum, you can see for yourself how uneven the stitches are in the left-leaning columns, especially compared to the more even stitches of the right leaning columns. SSK (bottom of second photo) looks somewhat better than psso (bottom of first photo), but neither looks terrific...

(ALTHOUGH, as I said at the beginning of this series, the loose sloppy top stitch in ssk or psso has a tendency to tighten up as the garment is worn and washed. And, as ssk or psso is tightening up in this way, k2tog is loosening up. With wear and blocking, the second stitch that got squeezed behind the first stitch in k2tog eventually manages to give up some of its slack, and the rightward leaning top stitch of k2tog gets a bit sloppier. It's true that ssk an k2tog never look exactly the same, but they look a whole lot more like twins after wearing and a couple of washings than they do when you are first creating them. So, once again, all this stuff about improving your left-leaning decreases is, in some measure, a marker of our right-now culture, where we want everything to be perfect RIGHT AWAY! and RIGHT NOW!)

Ahem! Well, if my little screed about right-now-ism hasn't deterred you, or if you are naturally a perfectionist, or if you just like to fool with stuff, then stay tuned for the next post, which will show the first of two techniques to improve these sloppy, left-leaning decreases. Until then, keep knitting...

(You have been reading TECHknitting on "left leaning decreases")


Tracy said...

I just like to fool with stuff....keep it coming please!!! :-)

Anna said...

You know, I'm not convinced that it's the manipulation of the right-hand stitch that causes the left-leaning decrease to look sloppier than the right-leaning. See, I knit in combined style, meaning that my ssk requires no manipulation whatsoever, as the stitches are already in the proper position for a left-leaning decrease. But ssk is still not as neat and tidy as k2tog, which does require me to turn stitches around.

I read an explanation of this phenomenon somewhere, but alas, I can't remember what the reason was. It was somehow related to how the first knit stitch in a column of rib can be a bit loose, or perhaps the two explanations were just given simultaneously.

catsmum said...

so glad to have you back :]

Sue J. said...

I am so glad you are back. Thank you, thank you.

Kamilla said...

Loving the fact that you are making me wiser.

Please don't ever take down this site; I would hate to loose all this great information.

- Just like others, I'm glad to be able to follow you again.

erasmus said...

I'm loving these technical details. You're a star for sharing your amazing intelect (jiva - posting as her cat erasmus)

Carrie S. said...

Oh, looking forward to the screed on combo knitting since I managed to unvent it (and spent a lot of time confused by lace patterns before I worked out what was going on).

Marjorie said...

Nice to have you back. I always have to fuss with the decreases because I knit combined, and so I'll welcome your eventual post. I sometimes rewrite the instructions if there aren't many (or fix the chart). And sometimes, on complicated lace, I just knit Continental to save my sanity. It is a tradeoff, though, because I knit much more neatly and evenly when I use the combined method.

I must confess that I haven't stared at my work as closely as Anna, but after reading her comment and your post, I'll do so.

Kitsune said...

So would deliberately wrapping stitches on the previous row to get opposite stitch mount, so you could do the left-leaning decs as k2tog as well, fix the issue?

--TECHknitter said...

Hi Anna!

Thanks for your comment. Unfortunately, my response to your comment must be deferred--until that time that TECHknitting takes up COMBINED KNITTING. My antique and aging brain might not remember your exact question when I get to that topic, so PLEASE, if I skip over it, help me out by asking again when the combined knitting posts go live on TECHknitting (somewhere in the future...) Thanks very much for writing.

Hi also to Kitsune:

You would think, logically, that changing the stitch mount (orientation) on the row before the decrease would take care of the problem, wouldn't you? And the fact is, that IS an undeniable improvement. You might want to experiment and see for yourself.

When I first set out to analyze the left-leaning decrease problem (years ago) I did come up with this as a possible solution. However, I ultimately rejected it. The first version of my answer to you set out all the reasons why. When I went to preview that comment, however, it was a mile long.

So, here's the deal: instead of posting the answer to your inquiry in this comment section, I cut and pasted it into a new file, and I'll expand this series on decreases by adding another post at the end--a post about alternative decreases, including the one you inquire about. (I think I'll call that part of the series the "Uber-techno-geek decrease post.")

In fact, some of the alternatives with which I experimented were very beautiful--ultimately earning rejection not because they were not lovely, even decreases, but because I thought them were too complicated, and thought that the two decreases I ultimately settled on gave more bang for the buck. (The two final "winners" of my experiments will be featured in the next two posts.)

So, the answer to your question is coming, but will be deferred.

*THANKS* though for asking--you sure made me think about this series more carefully, with the result that the series will be expanded to a fifth post.

To all the commenters:

Thank you for your kind words, and even more, for your questions! Sometimes, I wonder if I am just amusing myself with this blog, so it's very helpful to get feedback about future posts you would find interesting.

Thanks again


Anna said...

Reading your comment, I realized that I forgot to thank you for this series! I've been lurking for a while and I don't think I've ever commented on any of the posts. This blog is incredibly informative, and I always look forward to seeing new posts here. :)

kmkat said...

I like to save your posts for when I have the time to ponder them. Thanks for your blog -- I too like to know what's going on under the hood.

When are you going to put all this into a book? Seriously. Then I could buy it and have it forever (and hug it and squeeze it and call it George).

Ape said...

I am learning a lot, but I'm pretty sure this is a typo.

As the photos below demonstrate, left leaning INCREASES really are the "evil twin," in looks, at least, when compared to right leaning decreases.

it should read decreases not increases.

--TECHknitter said...

Hi Ape--thank you for your eagle-eyed catch. Off to fix that right now. Thanks again for taking the trouble to write. --TK